Identify the variation as direct, inverse, joint or combined. r=cs/t

Combined.

Step-by-step explanation:

Variation are generally of 4 types,

Direct Variation- When one of the variables increases or decreases, the other one increases or decreases.

Inverse Variation- When one of the variables increases, the other one decreases and vice versa.

Joint Variation- Where more than two variables are related directly .

Combined Variation- A combination of direct or joint variation, and indirect variation.

So in this case, r is in combined variation with s and t. r is in direct variation with s and inverse variation with t. And c is the proportionality constant.

y -5 = (-1/4)(x + 8)

step-by-step explanation:

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.